Square Footage of a Circle Calculator
Calculate the area of a circle in square feet using radius, diameter, or circumference
Calculate Circle Square Footage
Distance from center to edge of the circle
Circle Area Results
Example Calculations
16-foot Diameter Circle
Given: Diameter = 16 feet
Radius: r = d/2 = 16/2 = 8 feet
Area: A = π × r² = π × 8² = π × 64 = 201.06 sq ft
Alternative: A = π × d²/4 = π × 16²/4 = π × 256/4 = 201.06 sq ft
1524 cm Radius Circle
Given: Radius = 1524 cm
Convert to feet: 1524 ÷ 30.48 = 50 feet
Area: A = π × 50² = π × 2500 = 7854 sq ft
Half-Circle Calculation
For any circle: Half-circle area = (π × r²) ÷ 2
Example: 10 ft radius → Full: 314.16 sq ft → Half: 157.08 sq ft
Circle Formulas
Area
A = π × r²
Or A = π × d²/4
Circumference
C = 2 × π × r
Or C = π × d
Radius
r = d/2
Or r = C/(2π)
Diameter
d = 2 × r
Or d = C/π
Unit Conversions
1 foot = 12 inches
1 foot = 30.48 centimeters
1 yard = 3 feet
1 sq ft = 144 sq inches
1 sq yard = 9 sq feet
1 sq meter = 10.764 sq feet
Circle Tips
π (pi) ≈ 3.14159 for calculations
Radius is half the diameter
Area increases with the square of radius
Used for pools, gardens, patios, etc.
Understanding Circle Square Footage
What is Square Footage?
Square footage (also known as square feet, sq ft, or SF) of a circle is its area expressed in square feet. This measurement is essential for construction, landscaping, and design projects where you need to know how much space a circular area covers.
Common Applications
- •Swimming pool construction and liner sizing
- •Circular patio and deck planning
- •Garden bed design and mulch calculations
- •Flooring estimates for round rooms
- •Material cost calculations for circular projects
Calculation Methods
From Radius
SF = π × r²
Most direct method
From Diameter
SF = π × d²/4
When diameter is known
From Circumference
SF = C²/(4π)
When perimeter is measured
Important: Always ensure your measurements are in feet before calculating, or convert the result accordingly. 1 foot = 30.48 cm for metric conversions.